Collapsible portable ladder



Feb. 26, 1963 A. A. SILEN COLLAPSIBLE PORTABLE LADDER Filed March 7,1960 e m N w M United States Patent Office 3,378,953 Patented Feb. 26,1963 3,078,953 COLLAPSEBLE PQRTABLE LADDER Almer A. Siien, PelicanRapids, Minn, assignor to Siibo Enterprises Incorporated, St. Cloud,Minn, a corporation of Minnesota Filed Mar. 7, 196%, Ser. No. 12,997 4Claims. (Cl. 132-163) This invention relates to portable devicesconsisting of hingedly interconnected conventional ladder sections whichmay be employed either as fire .escape devices for use in buildings suchas dwellings, schools, oflices, and the like or for use as aconventional ladder, and is conceived and constructed for compactcollapsing and storage in a small space such as a closet and readilyextendable and attachable to a Window sill or the like for use outsideof the building when utilized as a first escape.

More particularly, this invention relates to an interlocking device foruse with collapsible portable devices comprising hingedly interconnectedeconventional ladder sections, and also particularly constitutes animprovement on my copending application, Serial No. 784,545, filedJanuary 2, 1959, relating to portable collapsible fire escape devices.

The aforementioned application relates to a portable fire escape deviceconsisting of hingedly interconnected rigid ladder sections which arereadily collapsible to compact side-by-side relationship for ease intransportation and storage and which is adapted to be readily andquickly secured to a window sill with the ladder sections in unfoldedcondition extended downwarly from the window on the outside of thebuilding to permit escape from the window to the ground when the normalexits from the building have been blockaded by flame and smoke.

An important object of my invention is a novel interlocking device whichis simple in design and inexpensive in construction and which is capableof maintaining the ladder sections of devices of the class abovedescribed in rigid non-collapsible alignment.

Still another object is an interlocking device of the class describedwhich works automatically without any help or assistance from theoperator to lock the ladder sections together as they move intoalignment with one another.

Another object is an interlocking device of the class described whichenables collapsible portable type fire escape devices of the type abovedescribed and set forth in the aforementioned application to be maderigid automatically as the ladder sections of the device unfold from topto bottom and is particularly useful in fire escape devices of this typewhere there is no vertical supporting wall structure immediatelyadjacent the device to permit the device to rest thereagainst and aidsin preventing undesirable flexing and movement of the ladder section asthe person progressively lowers himself to the ground and also aids inpreventing undue swaying thereof.

Still another object is a locking device which permits collapsible fireescape devices consisting of hingedly interconnected ladder typesections to be rigidly locked together for use as aconventional ladderwhen so desired.

Still another object is an interlocking device of the class describedwhich permits two or more hingedly interconnected conventional laddersections to be locked in aligned position to form a rigid ladder ofvariable length depending on the number of sections which are alignedand interlocked together.

These and other objects and advantages of my invention will more fullyappear from the following description made in connection with theaccompanying drawings wherein like reference characters refer to thesame or similar parts throughout the several views, and in which:

FIG. 1 is a front elevation of my device in extended condition with theladder sections in interlocked aligned relationship;

FIG. 2 is a side elevation of the same;

FIG. 3 is a side elevation of the same embodiment of the invention withthe ladder sections of the entire device compactly collapsed for storagein an upright position;

FIG. 4 is a transverse cross sectional view taken on the line 4-4 ofFIG. 1 and on an enlarged scale;

FIG. 5 is a front elevational view with portions broken away showing theladder sections interlockingly interconnected by the device of myinvention on an enlarged scale; and

FIG. 6 is a perspective view of one of the preferred forms of thelocking device of my invention.

Reference is now made to the drawings for a more dethe letters Sl, S2,and S-3, each as shown being identi{ cal in construction and comprisingin each instance a pair of parallel opposed spaced rigid rails 7preferably but.

not necessarily being constructed of very light channel members havingthe out-turned flanges 7a thereof disposed outwardly of the laddersection. Such materials as the number of difierent aluminum alloys arewell suited for my construction.

Each of said ladder sections includes a plurality of spaced, rigid rungmembers 8 which preferably are tubular and welded or otherwise rigidlysecured at their ends to the respective rails 7. It will be noted thatthe rungs 8 in each section are so arranged with reference to theelongated ra-ils 7 that the ends of the rails extend for a considerabledistance in each instance above or below the end rungs so that thespacing between the opposing end rungs of adjacent sections correspondsto the spacing between the rungs of each section to provide uniformlyspaced steps when the device is in unfolded extended condition.

The ends of the successive ladder sections Sl, S2, and 8-3 are hingedlycoupled together by a very strong and efficient hinge structure toprovide for rapid and sure extension of the structure from the collapsedand stored.

position shown in FIG. 3 to the unfolded positions of the laddersections shown in FIGS. 1 and 2. As shown, the lower ends of the rails 7of section S-1 are hingedly connected to the appropriate upper ends ofthe rails 7 of section S2 and the lower ends of section S2 are similarlyconnected to the upper ends of the rails 7 of section 8-3. The preferredembodiment of the efficient hinge coupling construction illustrated foreach hinge connection comprises a pair of opposed heavy hinge plates 9and 14) respectively. The inner plate 9 of each pair of hinge plates hasan offset medial portion 9a to clear the flanged edges 7:; of thechannel rails 7 while the outer hinge plate It) is provided with anoffset central portion 16a to adequately clear the out-turned flanges 7aof the rail channel members. The flat end attachment portions of eachpair of the hinge plates 9 and 10 are pivotally secured to theappropriate medial portions of the appropriate rail 7 by common heavynutted bolts 11 and the outer ends of the bolts are preferably slightlyswedged to positively prevent disconnection of the bolts of the coupledparts.

If the hingedly interconnected ladder sections above described are to beemployed for use as a fire escape, then the following mechanism isprovided. At the upper end of the first ladder section 8-} and slidablysecured for upward extension from each of the rails 7 of said section, Iprovide very strong attachment and sup port means for cooperating withwindow sills varying substantially in width and dimensions. As shown,the upper portions of each of the rails 7 of the first ladder section3-1 are provided with rigid inverted lJ-shaped sill engaging rods 12which have inward vertical shanks 12a slidably mounted for longitudinalextension in heavy angle brackets 13 which, as shown, are pivotallybolted by heavy bolts to the respective upper ends of the rail 7 of theladder section S1. The flat pivotally attached portions 131: of theangle brackets are confined for restricted swinging movement between theoutstanding flanges 7a of the respective rails. The'outwardly disposedflanges 13b of the angle brackets are centrally apertured to accommodatethe heavy shanks 12a of the sill engaging rods 12, and shanks 12 1 attheir lower ends are provided with permanently and rigidly attachedenlarged abutments 12b. Thus, the shanks 12a are freely verticallyextensible and retraetible with respect to the rails upon which they aremounted. This enables the U- shaped members 12 to be swung inwardlytewards one another to overlie and rest upon the upper ends of therailsupon which they are mounted for compactness during storage. Thepivotal mounting of the brackets 13 enables the shanks 12a to beslightly tilted out of yer tical alignment with one another to enablethe U-shaped portions of the hooks to lie in parallel side-by-siderelationship when swung inwardly towards one another.

The Ll-shaped supporting and securing members '12 include medialhorizontal rod portions 120 and depends hook arms 1212 which terminatein free ends. The members 12 may be swung outwardly to the positionshown FIGS. 1 and 2 to lie in planes substantially perpendicular to thewide elongated laces of the channel rails 7 or they may be swung whenslightly extended by raising of the shanks 12a above the positions shownin GS- 1 an 2 to Cause t medial por io s or rm 12c. t o e the we e o hdd r sect on. bo e tin funss of th secti n s ho n 41 .FIG-v 3-v n sa dast i w f c e pos n th wo suppor and e cu i mea s 2 members a e ry oselyollap ed 14 being 'freely s'lidably mounted on eachof the rail seetio'ns7. The locking channels 14 enclose the rail members7 with the sides 14thereof overlying the outer faQ MQf the rail flanges formed by the flangportions- 721 and 7b thereof and lie in contiguous sliding relationtherewith for guided longitudinal movement of the lock-v ing channels 14on the rails 7. The channel sides 14;: are, provided with 'inturnedflange or feet portions 14b. which overlie the ends of the flanges 7b ofthe rails 7 in contiguous sliding relation therewith and prevent lateralremoval of the channel 14 from the rail 7. The medial portion 14c lyingbetween the sides 14a is outwardly ofiset a sufiicient distance to forma longitudinal.- ly andoutwardly extending groove or relief portion ofsutficient depth to freely clear the medial portions 10a ofthe. hingeplates 10 which extend outwardly beyond the. edges of the rail 7. Themedial portion 14c is connected with the sides 14a at each end thereofby portigns 14d which lie in spaced apart generally parallel oppositionto the inturned flange portions 14b and contiguQll$1y overlie the endsof the flanges 7a of the rail 7, the portions. 14g, 14]), and 140cooperating to permit free sliding guided movement of; the interlockingchannel 14. on the rail ,7 while preventing any appreciable lateral ortransverse movement with respect thereto.

The medial portion 14c is provided with a depressed portion 15intermediate the ends of the channel 14 and approximately midway of suchends to provide an inwardly extending abutment surface. The depressedabutment 15 extends inwardly a suflicient distance to enable it toreadily abut with and engage the upper surface of the medial portion 10aof the hinge plate 10 to limit downward movement or" the channel 14 andinterlock the adiacent hingedly connected ladder sections by overlappingthe adjacent end portions of the opposing rails and thereby preventrelative movement therebetween.

As best seen in FIGS. 1, 2 and 5, when the channel 14 is in lookingposition, the depressed abutment member 15 engages the out-turned medialportion 10a of the hinge plate 1.0, with the upper portion of thechannel 14 overlying the lower portion of the upper ladder section andthe lower portion of the channel 14 overlying the upper portion of thelower ladder section. Thus, the channel 14 provides a rigidinterconnection between the adjacent ladder sections and prevents anycollapsing movement therebetween.

When not in use, the channel sections 14 are disposed completely on oneladder section intermediate the ends thereof as shown by the broken linepositions of FIGS.

1 and 2 and also shown in FIG. 3. When it is desired to rigidlyinterconnect two or more of the adjacent ladder sections, the laddersections are simply brought into alignment with one another, whichcauses the locking channel section 14 to move by force of gravity fromtheir broken line positions of FIGS. 1 and 2 to the interlocking solidline positions shown in FIGS. 1 and 2, the downward movement of themember 14 being automatically arrested by engagement of the depressedabutment member 15 with the medial portion Ida of the hinge plate 10.

Thus, the locking device of my invention operates automatically tointerconnect rigidly the adjacent hingedly the hinge mechanisms toenable the ladder sections to be' collapsed into side-by-siderelationship as shown in FIG. 3.. Because the channel sides 14a are thinand fiat, they do not intefere. with the collapsed nature of thesections as shown in FIG. 3.

From the foregoing, the advantages of my invention are readily apparent.The interlocking device is substantially fully automatic and extremelyeasy to operate. The manner in which it freely moves to interlock theadjacent ladder sections in rigid relationship is particularly importantwhen the device is used as a fire escape mechanism. It enables thecollapsed folded sections to be simply hung out of the window andattached to the window sill and simply allowed to naturally unfold toextended position and as the sections unfold and come into alignmentwith one another the locking channels automatically slide intointerlocking relationship to provide an integral unit structure, thusavoiding the undesirable feature of having a flexible fire escape whichwill sway and bend as the person lowers himself to the ground thereonand eliminates the necessity for rigidly interconnecting the sectionsprior to extending the fire escape from the window, which not only isawkward and inconvenient but which is dangerous and time consuming wherea matter of seconds can be the diiference between life and death to aperson attempting to. escape when a fire is raging in a building. Thisinterlocking arrangement also permits elimination of the wall spacingmembers which were previously employed and disclosed in myaforementioned application. The interlocking device of my invention alsopermits hingedly interconnected ladder sections to be rigidly aligned toeasily convert the collapsed structure into a rigid elongate structureand also permits a selective number of these hingedly joined laddersections to be rigidly united in as many sections' as desired to form aladder of the length desired. Thus, two, three, four or more sectionsmay be rigidly ins terconnected to form as long a ladder as desiredwithithe remaining sections if any being permitted to remain incollapsed nested condition against the lowermost of the rigidlyinterconnected ladder sections. The automatic operation of myinterlocking device is also important when employed with collapsiblefire escape devices since it requires no manually operated parts whichmight be difficult or impossible for certain persons such as children orthose which are old, feeble or sick to successfully manipulate, andenables the device to be carried to the window and mounted thereon whilein collapsed condition, with the interlocking of the sections takingplace automatically as the sections unfold into alignment with oneanother.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the various partswithout departing from the scope of my invention.

What is claimed is:

1. In a device having a plurality of ladder sections hingedly connectedat their adjacent ends for compact folding of the sections into side byside relationship in which the ladder sections include a pair of spacedrails interconnected by a plurality of transversely disposed rungs,means for detachably locking the sections in rigid alignment with oneanother comprising an elongate channel member telescopically mounted onthe rail of one of said sections and adapted for free longitudinalmovement thereon back and forth past said rungs, said member freelysliding downwardly into overlapping simultaneous engagement withadjoining rails when they are in generally vertical alignment with oneanother thereby overlaying the hinge connection between said rails andpreventing hinged movement therebetween, outwardly protruding firstabutment means provided by said hinge connection, and inwardly extendingsecond abutment means carried by said channel intermediate the endsthereof cooperatively engaging said first abutment means when inoverlapping locking position and preventing further downward movement ofsaid channel member, said member when in locking position being capableof free upward unlocking movement to release the hinge connection forfolding of said sections.

2. A device having in combination a plurality of rigid ladder sections,each comprising a pair of spaced rails interconnected by a plurality ofvertically spaced rungs, said sections being successively hingedtogether at substantially abutting end portions thereof for compactstoring relation when in collapsed parallel side by side position, andcharacterized by hinge connections between the lower ends of the railsof one section and the upper ends of the rails of an adjacent section,each hinge connection comprising a pair of spaced parallel platespivoted at their upper ends to and on opposite sides of the lower end ofthe upper ladder section and pivoted at their lower ends to and atopposite sides of the upper ends of the rails of said lower section,said plates being adapted to receive the edge portions of the railstherebetween when folded, one of said plates having an outwardly offsetportion providing a first abutment element, and means for rigidlyinterlocking adjacent sections in aligned relationship, said meanscomprising an elongate interlocking member mounted for free slidinglongitudinal movement on a rail of the upper section of adjoining laddersections, and second abutment means carried by said interlocking memberapproximately midway between the ends thereof and extending inwardlytowards said offset portion, said member being adapted to fall freelyinto overlapping relationship with the end portions of the opposingrails of adjoining sections when in substantially vertical alignmentwith one another, said first and second abutment means cooperativelyengaging one another to prevent downward movement of said locking memberpast overlapping interlocking position and maintaining said member insaid position.

3. In a device having at least two conventional ladder sections eachconsisting of side rails and a series of transverse rungsinterconnecting said rails and in which the sections are hingedly joinedtogether in end to end aligned relationship by hinge meansinterconnecting opposing end portions of corresponding aligned railmembers on adjacent sections, and wherein said hinge means extendlaterally outwardly beyond the side faces of said rails and provide anabutment, a channel member telescopically mounted on one of said siderails of the upper of two adjoining sections and overlying the outerface and edges thereof for free sliding movement thereon throughoutsubstantially the entire length thereof without interference from therungs, the portion of the base of said member overlying the outer faceof the rail in alignment with said abutment being outwardly concavedalong the entire length thereof, the concavity being of sufiicient depthto enable said member to pass freely over said abutment, said memberhaving an inwardly depressed portion in the wall of said concavitylocated approximately midway between the ends of said member andproviding a stop member adapted to cooperatively engage said hingeabutment, and limit downward movement of said member and maintain it inoverlying relationship with said hinge when said sections are invertical operative position and in simultaneous locking engagement withthe exposing end portions of said rail members to thereby preventhinging movement between said later sections, said member when inlocking position being capable of free upward movement on the upper railsection on which it is mounted to free the hinge for folding of saidsections.

4. A collapsible folding ladder device comprising a plurality of rigidladder sections, each having a pair of space rails consisting ofparallel fiat strip portions integrally united by a thin web portion,the rails of each section being interconnected by a plurality ofvertically spaced rungs extending between and connected to the webportions of said rails, said sections being successively hinged togetherat abutting end portions thereof for folding of said sections intocompact parallel side-by-side relationship by hinge connections betweenthe lower ends of the rails of one section and the upper ends of therails of an adjacent section, each hinge connection comprising a pair ofspaced elongate hinge plates whose end portions are pivotally connectedto opposite sides of the web portions of the rails coupled thereby, saidhinge plates having medial portions for enclosing therebetween theopposed flat strip portions of the coupled rail sections when in foldedcondition, said hinge plates preventing relative lateral movementbetween adjacent ladder sections, and an elongate interlocking membermounted for free sliding longitudinal movement on a rail of one of saidsections and adapted to fall freely into overlapping relationship withthe adjacent opposed end portions of adjoining sections when insubstantial vertical alignment with one another, and stop means forarresting the free falling movement of said member when it has reachedoverlapping interlocking position and holding said member in saidposition.

References Cited in the file of this patent UNITED STATES PATENTS298,660 Bessier May 13, 1884 389,696 Fink Sept. 18, 1888 1,003,407Abrams Sept. 19, 1911 1,177,557 White Mar. 28, 1916 1,196,419 BanyovitsAug. 29, 1916 1,785,342 Gilbert Dec. 16, 1930

1. IN A DEVICE HAVING A PLURALITY OF LADDER SECTIONS HINGEDLY CONNECTEDAT THEIR ADJACENT ENDS FOR COMPACT FOLDING OF THE SECTIONS INTO SIDE BYSIDE RELATIONSHIP IN WHICH THE LADDER SECTIONS INCLUDE A PAIR OF SPACEDRAILS INTERCONNECTED BY A PLURALITY OF TRANSVERSELY DISPOSED RUNGS,MEANS FOR DETACHABLY LOCKING THE SECTIONS IN RIGID ALIGNMENT WITH ONEANOTHER COMPRISING AN ELONGATE CHANNEL MEMBER TELESCOPICALLY MOUNTED ONTHE RAIL OF ONE OF SAID SECTIONS AND ADAPTED FOR FREE LONGITUDINALMOVEMENT THEREON BACK AND FORTH PAST SAID RUNGS, SAID MEMBER FREELYSLIDING DOWNWARDLY INTO OVERLAPPING SIMULTANEOUS ENGAGEMENT WITHADJOINING RAILS WHEN THEY ARE IN GENERALLY VERTICAL ALIGNMENT WITH ONEANOTHER THEREBY OVERLAYING THE HINGE CONNECTION BETWEEN SAID RAILS ANDPREVENTING HINGED MOVEMENT THEREBETWEEN, OUTWARDLY PROTRUDING FIRSTABUTMENT MEANS PROVIDED BY SAID HINGE CONNECTION, AND INWARDLY EXTENDINGSECOND ABUTMENT MEANS CARRIED BY SAID CHANNEL INTERMEDIATE THE ENDSTHEREOF COOPERATIVELY ENGAGING SAID FIRST ABUTMENT MEANS WHEN INOVERLAPPING LOCKING POSITION AND PREVENTING FURTHER DOWNWARD MOVEMENT OFSAID CHANNEL MEMBER, SAID MEMBER WHEN IN LOCKING POSITION BEING CAPABLEOF FREE UPWARD UNLOCKING MOVEMENT TO RELEASE THE HINGE CONNECTION FORFOLDING OF SAID SECTIONS.